MORPHOLOGICAL OBSERVATIONS ON DINOPHYSIS SPECIES (DINOPHYCEAE) FROM MEDITERRANEAN COASTAL WATERS

Morphological aspects of various Dinophysis species (e.g. D. sacculus, D. fortii and D. acuminata) collected from Mediterranean coastal area s (southern Italy) are described. Data on the fluorescence of Dinophys is are given in addition to cell details in scanning electron and ligh t microscopy. Specimens of D. sacculus from Tyrrhenian brackish waters , where this species has been associated with slight DSP - toxicity of mussels, display high variability in cell shape and size, whereas the thecal ornamentation has a regular pattern. Cells of D. sacculus, as well as D. acuminata from the Straits of Messina, autofluoresce bright red and yellow - orange, indicating the possible presence of both chl orophyll and phycobilin pigments. Globular components similar to food vacuoles, were observed inside a few specimens of the D. acuminata com plex and in D. rotundata cells, further supporting the respective mixo trophic capability and the heterotrofic behaviour of these dinoflagell ates.